| 1. | One strain possessing hydantoinase activity were isolated and named bt811 . it was proved that the bt811 was a new d - hydantoinase - producing strain by gene separation and sequence analysis
后经基因分离和序列分析，证实bt8ll为1株新的d一乙内酞脉酶产酶菌株。 |
| 2. | And strain ss - ori is sinorhizobium sp . according to the " blast " data . in addition , a hydantoinase gene ( 1440bp ) from yz - ii6 was amplified by pcr with genomic dna as the template
我们还利用pcr方法从菌株yz - 6基因组中克隆得到了海因酶的基因( 1440bp ) ，并构建了表达质粒pet3a - hdtase 。 |
| 3. | 3 . its shown from the results of dna digestion , hydantoinase gene amplification , rapd , eric - pcr etc , that the electrophoretic patterns of the products are obviously different form the original one
分别提取的基因组后进行酶切分析、海因酶基因的扩增、 rapd 、 eric - pcr等检测，两者均呈现不同的电泳图谱。 |
| 4. | Two dna fragments encoding d - hydantoinase gene were amplified by pcr from chromosome dna of pseudomonas putida yz - 26 and sinorhizobium morelense ss - ori , respectively , and confirmed by dna sequence analysis
序列分析表明，来自yz - 26菌的d -海因酶基因全长1440bp ，编码479氨基酸，基因序列已被genbank登录( ay387829 ) ，被确定为一个新基因。 |
| 5. | Hydantoinase ( ec 3 . 5 . 2 ) hydrolyzes its substrate 5 ' - monosubstantial hydantoin to enantiomerical n - carbamyl - amino acids and in turn , the resulting product can be chemically or enzymatically converted into the corresponding optically active amino acids
海因酶( hydantoinase ， ec3 . 5 . 2 ) ，是一类催化海因、 5 ’ -单替代海因及其衍生物环酰胺键断裂的酰胺水解酶。 |
| 6. | During cloning hydantoinase gene from the original strain ss - ori , we occasionally picked up a colony ( yz - ii6 ) which occurred a high hydantoinase activity . a series of experiments were performed to confirm whether this strain was the same as the original one
我们在克隆出发菌株ss - ori海因酶基因的过程中，偶然得到了一个能呈海因酶阳性反应的菌落，定名为yz - 6 ，并做了较为细致的研究。 |
| 7. | The enzyme is homologous dimmer with molecular mass 102600 as determined by gel filtration on hplc and subunit mass 52042 as determined by maldi - tof mass spectrometry . the optimal ph of d - hydantoinase is at near 9 . 5 and the optimal temperature is at 45
通过对其生化性质的研究表明，其单体m _ r为52042 ，天然m _ r为102600 ，最适ph为ph9 . 5 ，最适温度为45 ，不同的二价金属离子对酶活性有不同的影响。 |
| 8. | By the technology of gene cloning , bioconversion of d - amino acids with engineered cells containing d - hydantoinase and d - carbamoylase would be expected to overcome the drawbacks presented by using the original strains described above . according to the reported amino acid sequence of d - hydantoinases , two primers were designed and synthesized
本文根据文献报道的海因酶基因序列及大肠杆菌对密码子的偏爱性分别设计了正向及反向引物，以基因组dna为模板，利用pcr技术扩增得到菌株pseudomonasputidayz - 26和sinorhizobiummorelensess - ori的d -海因酶基因。 |
| 9. | Puc18 - 169 was a subcloned plasmid containing the whole operon sequence of l - hydantoinase from arthrobacter bt801 which can convert 5 - benzylhydantoin to l - phenylalanine . hydantoin hydrolase which is responsible for the ring opening of hydantoin is one of the components of hydantoin utility enzymes of arthrobacter bt801 . n - carbamoylase is a part of hydantoinase operon which can transform n - carbamoylamino acids into the corresponding amino acids
节杆菌( arthrobacter ) bt801是由军事医学科学院生物工程研究所保存的l -乙内酰脲酶产酶菌株， puc18 - 169是由本室构建的含有节杆菌bt801的l -乙内酰脲酶完整操纵子序列的亚克隆质粒。 |
| 10. | With the procedures , the overall recovery of enzymatic activity reached 20 % and the specific activity for substrate hydantoin was about 4 u / mg protein . the purification factor was about 4 . 7 folds with the purity about more than 95 % as estimated by sds - page analysis . d - hydantoinase gene from strain ss - ori was cloned to five different vectors to be five recombinant plasmids and in turn to transfer into five different e . coli strains , respectively
对其中产酶活性最高的一工程菌pexsec一hdt /云coljblz ] ( de3 )海因酶的表达条件进行了研究，目的蛋白的表达量约占总菌蛋白的20 % ，其酶活力为0 . 92u / ml ，约是原始菌株的d一海因酶表观活性的4 . 6倍。 |
